The Hydro Trip Pressure Sub is a pressure-activated device installed in the tubing string below a hydrostatically actuated tool, such as a packer. It provides a controlled means of setting the packer and, with continued pressure application, subsequently activates the Hydro Trip Sub.

The packer is set by circulating a ball through the tubing to the ball seat in the Hydro Trip Sub. After the packer is set, additional pressure shears the screws in the shear ring, allowing the ball seat collet to shift into the collet relief area. This action enables the ball to pass through the Hydro Trip Sub, leaving the sub fully open and unrestricted for production